Multi-Compartment Tray-Less Package With a Rigid Frame

ABSTRACT

A tray-less multi-compartment plastic flexible package has two outermost films comprising crystallizable polymer, at least two products, and at least one internal film comprising crystallizable polymer. The internal film is interposed between the two products and the outermost films. A peripheral circumferential continuous seal seals the two outermost films and the internal film together in a sealing area and delimits two sealed compartments each enclosing one of the at least two products. The crystallizable polymer is at least partially crystallized in the sealing area.

The presently disclosed subject matter relates to packaging, forexample, a multi-compartment tray-less package wherein at least twoproducts in stack are contained into individual compartments delimitedby films, in particular to a multi-compartment tray-less packagecharacterized by a peripheral rigid frame obtained by partialheat-induced crystallization of the films along the sealing area duringthe sealing operation.

BACKGROUND

In the field of packaging, there are several applications in whichtraditional mono-compartment packages, namely packages in which thewhole product is enclosed in a single compartment, are not satisfactorywhile a multi-compartment arrangement—in which each single item orportion of a product is packaged individually—would be particularlyadvantageous.

For instance, in the field of food packaging, in particular of packagingof sliced products (cheese, processed meat, salmon, etc.) the existingmono-compartment packages show some drawbacks: in particular afteropening, leftovers are subjected to rapid drying and unpleasantorganoleptic changes and, unless consumed quite soon or frozen, they aregenerally wasted.

Furthermore, the shelf life of food products traditionally packagedunder modified atmosphere or under vacuum, is drastically shortened whenthe mono-compartment package is opened.

Finally, different food products not always can be combined in the samemono-compartment package because of odor migration (e.g. salami and dryham) or taste cross contamination (e. g. cheese and processed meat).Another disadvantage of mono-compartment packages—particularly ifcomprising important amount of sliced food products—is that the slicesstick to each other and are difficult to be separated, so very often aredamaged when removed from the package.

In the medical field, sterilized items such as cannulae, plasters,needles, bandages etc, when packaged in mono-compartment packages, mustall be used immediately after removal otherwise contamination byenvironment bacteria or drying of dipped medicated items may occur.

In order to overcome the above problems, multi-compartment packagingsystems, which provide for individually packaged items or for packagingof single quantity of products, have been provided.

U.S. Pat. No. 4,069,348 (L.D. Schreiber Cheese Company) discloses asealed package wherein a plurality of portions of products in a stackare hermetically sealed into individual compartments by internal filmswhich are releasably sealed to a backing board. When an individualportion of product is removed, all others remain hermetically sealed.

WO 8702965 (Garwood LTD) discloses a method to manufacture a package forskin wrapped food comprising a base—i.e. a rigid tray—and a lid with agas between the base and the lid in order to preserve the foodproperties. The package also comprises a flexible and gas permeable webof skin wrapping plastics material over the base and the food. Amulti-compartment version of this package comprising a rigid containeris disclosed. Useful plastics materials are polyvinyl chloride (PVC) andpolyethylene (PE).

WO8800907 (Garwood LTD) discloses an improvement of the method ofWO8702965. The package comprises a rigid tray made of PVC andpolyethylene terephthalate (PET) which contains skin wrapped food. Saidfood is plastered with a flexible and gas permeable web made of plasticmaterial which is sealed onto the rim of the tray. The package alsocomprises a gas-impermeable lid made of PET/PVC/PET which can have acompartment to store sauce or cutlery.

DE 4440727 (Beiersdorf AG) discloses a package containing at least 2plasters which are separated by a layer of material and which areenclosed between upper and lower cover layers, wherein the layers may bemade of several different polymers. The layers are bonded together bysealing, cold sealing, gluing or their combinations.

These existing multi-compartment packages show many drawbacks.Multi-compartment packages known in the art need a supporting tray or athick backboard to confer rigidity to the system. Trays significantlyincrease the volume of the packages and the ratio between the weight ofthe plastic materials and the weight of the packaged item, resulting inless sustainable packages.

In addition the presence of trays enhances manufacture and disposalcosts: in fact it brings additional manufacturing steps related to theproduction and shaping of the supporting tray, causing further waste ofenergy and time and, at the end, increasing costs.

Finally, the tray and the lids or wrapping films of multi-compartmentpackages of the prior art are made of different materials, thus makingrecycling and/or disposal of the entire package more troublesome.

There is still the need for a light and sustainable multi-compartmentpackage which allows:

-   -   to preserve single portions of different or same product(s),        also of air sensitive products, and to use them individually,    -   to easy open the compartment which contains each single portion,    -   to avoid cross contaminations (odors, taste, bacteria)    -   to prevent sticking and breaking of sliced products        said package being sufficiently rigid to be handled,        transported, stored and exposed even in the absence of an        additional thick plastic support structure, such as a tray.

SUMMARY

One or more embodiments of the presently disclosed subject matter mayaddress one or more of the aforementioned problems. In an embodiment, amulti-compartment tray-less package having at least two products instack are contained into individual compartments wherein eachcompartment is comprised between two internal films, or an internal filmand an outermost film. The films may be peelable. The films comprise acrystallizable polymer. The package further comprises a continuous rigidframe obtained by partial heat-induced crystallization of thecrystallizable polymer during the sealing operation. Such a package doesnot require any supplemental tray, with the advantage of reducingoverall costs and lowering its environmental impact. The package showsseveral advantages such as preventing drying of leftovers, maintainingsterility, avoiding cross contamination among different products etc . .. with a significantly reduced consumption of material compared toconventional tray or backboard based multi-compartment packages.

In an embodiment of the present invention a tray-less multi-compartmentpackage of individually sealed compartments comprises

-   i) two outermost films,-   ii) at least two products in stack,-   iii) at least one internal film interposed between the at least two    products in stack,-   iv) a peripheral circumferential continuous seal which seals the    films in stack together and delimits at least two sealed    compartments in stack, each compartment enclosing at least a product    of said at least two products in stack,    characterized in that the films comprise a crystallizable polymer    and the crystallizable polymer is at least partially crystallized in    correspondence of the sealing area thus providing a peripheral    circumferential continuous rigid frame.

Another embodiment of the present invention is a method formanufacturing the multi-compartment package, such a method comprisingthe steps of:

-   i) providing two outermost and at least one internal, optionally    pre-cut, crystallizable films;-   ii) providing at least two products to be packaged;-   iii) stacking an outermost film, the product(s), the internal    film(s)—alternating the products and the internal film(s)—and the    other outermost film, up to the desired number of compartments is    obtained;-   iv) sealing and simultaneously crystallizing the stack of films    along a peripheral circumferential continuous sealing area thus    providing a peripheral circumferential continuous rigid frame, and-   v) optionally, simultaneously or afterwards, cutting the stack of    films all around outside the frame thus providing the    multi-compartment package;    or, alternatively the steps of:-   a) providing two outermost and at least one internal, optionally    pre-cut, crystallizable films;-   b) providing at least two products to be packaged;-   c) placing in stack an outermost film, a product and an internal    film;-   d) sealing and simultaneously crystallizing the stack of films along    a peripheral circumferential continuous sealing area thus providing    a peripheral circumferential continuous rigid frame;-   e) optionally, simultaneously or afterwards, cutting the stack of    films all around outside the frame thus providing the first    compartment of the package;-   f) placing a stack of “a product/a film” or of “a film/a product/a    film”, onto the compartment formed in steps c) to e);-   g) repeating point d) to f) for each new compartment, up to the    desired number of compartments is obtained, thus providing the    multi-compartment package;    or, alternatively the steps of-   A) providing two outermost and at least two internal, optionally    pre-cut, crystallizable films;-   B) providing at least two products to be packaged;-   C) placing in stack a film, a product and a film;-   D) sealing and simultaneously crystallizing the stack of films along    a peripheral circumferential continuous sealing area thus providing    a peripheral circumferential continuous rigid frame;-   E) optionally, simultaneously or afterwards, cutting the stack of    films all around outside the frame thus providing the first    compartment of the package;-   F) manufacturing at least another compartment following steps A to    E;-   G) stacking the first and the new compartment(s), optionally placing    a product in between adjacent compartments;-   H) sealing or gluing together the first and the other new    compartment(s), simultaneously or one after the other if more than    two, up to the desired number of compartments is obtained, thus    providing the multi-compartment package.

Definitions

As used herein the term “tray-less package” refers to a package in whicha rigid tray, container, receptacle, backing board, plate, andequivalent rigidity-conferring support commonly used in the packagingfield, placed outside the sealed compartments and to which the films areconnected (i.e. sealed, glued etc.), is absent. The term “tray-lesspackage” does not exclude the presence of pads or other flexible,semi-rigid or rigid supports enclosed within one or more of the sealedcompartments (i.e., does not exclude a completely enclosed support)where the enclosed support is not sealed together with the films instack but is completely enclosed within the sealed compartment.Similarly, the term “tray-less package” does not exclude that thepresent package may be further placed into a container, providing thatit is not connected to it by circumferential sealing, gluing etc.

As used herein the term “multi-compartment package” refers to a packagehaving more than one compartment in stack. This package contains morethan one portion and/or more than one item of one or more products instack, each portion and/or each item being enclosed in an individuallysealed compartment.

As used herein the terms “compartment” and “sealed compartment” refer toa part of the present package delimited by two adjacent films—i.e. twointernal films or an internal film and a outermost film—sealed togetheralong a peripheral circumferential continuous seal. Each compartmentencloses at least a product.

As used herein in conjunction with a compartment, the term “outermostfilm” refers to a plastic film positioned closest to the outside of thepackage relative to the internal films wherein one of the surfaces of anoutermost film is in contact with a product and the other surface of theoutermost film is not.

As used herein the term “product(s)” refers to both countable anduncountable products. In case of countable products, the term “products”refers to at least two items of said product(s) while in case ofuncountable products, it refers to at least two portions.

As used herein the term “two products” refers to two items or portionsof products packaged in the present package. The “two products” maybethe same or different. If the two products are the same, the packagecontains either two items or two portions of that same product.

As used herein the term “single portion of product” refers to an amountof product which is contained in a compartment of the package.

Any arrangement of the one or more portions and/or items of the one ormore product(s) in the sealed compartments of the presentmulti-compartment package is intended to be within the scope of thepresently disclosed subject matter—i.e. different items or portions ofone product, each one singularly enclosed in a sealed compartment suchas sterilized bandages or slices of ham; different items or portions oftwo or more products each one singularly enclosed in a sealedcompartment such as slices of cheese/slices of ham/slices of salami eachone packaged in a different compartment; different items or portions ofa single product, more than one item or portion being enclosed in asealed compartment such as two sterilized patches in the samecompartment; different items or portions of two or more products, morethan one item or portion of different products being enclosed in thesame compartment such as a sterilized bandage and a plaster together inthe same compartment etc.

As used herein the term “internal film” refers to a plastic film of thepackage wherein one of its surface is in contact with the product(s)enclosed in a first compartment and the other surface is in contacteither with the product(s) of a second compartment or with the surfaceof another internal film.

As used herein, the term “film” includes flexible plastic webs,regardless of whether it is a film or a sheet or a laminate. Typically,the film used in the package object of the presently disclosed subjectmatter has a thickness from 100 μm to 5 μm; more preferably from 60 μmto 7 μm, even more preferably from 40 μm to 10 μm.

The outer films and the internal film(s) may have the same thickness,however they may also be of different thickness.

As used herein, the phrase “which seals the films in stack together”when referred to the peripheral circumferential continuous seal meansthat all or, in alternative, some of the films in stack are sealedtogether while some others may be glued.

In case only some of the films are sealed together, the package may beassembled by stacking the sealed compartments and by gluing themtogether, as described for instance in a third variant of themanufacturing process of the present package. In such a case, thecrystallinity induced in the sealing area of each single independentcompartments is sufficient to confer a suitable rigidity to the finalframe after assembly of the package by gluing.

As used therein, the term “frame” means the rigid peripheralcircumferential continuous partially crystallized edge obtainable bysealing the outermost and internal plastic film(s) of the package toeach other in stack.

As used herein the term “rigid” refers to the flexural rigidity of theframe. Independently of the test method adopted to evaluate the rigidityof the frame, in the present contest “rigid” means that the frameobtained by sealing the outermost and internal plastic film(s) of thepackage to each other in stack has a rigidity higher than the rigidityof the same stack of outermost and internal plastic film(s) beforesealing.

Flexural resistance to bending can be measured for instance by DynamicMechanical Analysis (DMA) according to ASTM 4065 or with a dynamometerin line with ASTM D790 and can be expressed in N/m² as resistance of theframe to bending.

Rigidity requirements of the present package may change depending on theproducts packaged, its final use and destination etc. However theskilled person is able to select both crystallizable polymer(s) andoptimal sealing conditions in order to impart to the package thestiffness required by the intended use.

The stack of outermost and internal plastic film(s) before sealing israther flexible. After sealing, the at least partial crystallization ofthe films induced by heat and pressure in correspondence of the sealingarea, forms the frame and imparts a rigidity which is higher than therigidity of the starting stack of films. The frame, depending on thelevel of crystallization induced, on the thickness and width of thesealing area etc., may still be partially flexible or semi-rigid, but ithas to be understood that its rigidity is always higher than therigidity of the starting stack of films before sealing.

As used herein, the term “sealing” refers to the bonding of plasticfilms obtainable by application of all those sealing techniques whichare able to induce an at least partial crystallization of thecrystallizable polymer(s) of the films along the sealing area, such asfor instance hot bar sealing or ultrasonic welding techniques.

As used herein, the terms “crystallizable”, when referred to polymers,plastic films or sheets, means that the polymer, the film or sheetcomprising the polymer can crystallize under sealing conditions, e.g.upon heating and/or compression.

As used herein, the terms “crystallized or crystalline” polymer, resin,polyester etc. refer to homopolymers and copolymers, compoundedformulations or recyclates, having a definite melting temperature.

As used herein, the term “crystallizable polymer(s)” refers to polymer,homopolymers, copolymers, blends, compounded formulations or recyclates,resins, etc able to crystallize at the sealing conditions adopted duringthe sealing step. Examples of suitable crystallizable polymers arecrystallizable polypropylene(s) homo- or copolymers, high densitypolyethylenes (HDPEs), medium density polyethylenes (MDPEs), polyesters,biodegradable polyesters such as polylactic acids (PLAs), polyamidessuch as PA6, preferably added with nucleating agents, polystyrenes (PS),more preferably crystallizable polyesters, and their blends. As usedtherein, the expressions “polymer or polypropylene or polyethylene orpolyester (based)”, when referred to the film or film composition meansthat the film is a mono- or multilayer film comprising at least 30% byweight, with respect to the total weight of the film, of acrystallizable polymer or polypropylene or polyethylene or polyester,preferably of a crystallizable polyester, more preferably at least 50%,60%, 70%, 80%, 90% or 95%.

When the crystallizable polymer is for instance a polyester, with theterm “crystallizable polyester” a polyester able to crystallize attemperatures typically ranging from 140° C. to 220° C.—temperaturesgenerally adopted in the sealing stage of the manufacturing process—ismeant.

As used herein the phrase “the polymer is at least partiallycrystallized” refers to a polymer which is at least partiallycrystalline. As used herein the phrase “at least partially crystallinepolymer” refers to a polymer, for example a polyester, which has apercentage of crystallinity higher than 15%, preferably higher than 20%,more preferably higher than 25%, even more preferably higher than 30%.

The melting temperature of the polymer(s) and their crystallinity can beevaluated by Differential Scanning Calorimeter (DSC) or by otherequivalent procedures well known in the art.

For instance, DSC may be used to determine the degree of crystallinityof thermoplastic polymers through the measurement of the enthalpy offusion (measurable following ASTM E793) and its normalization to theenthalpy of fusion of a 100% crystalline polymer (see B. Wunderlich,Thermal Analysis, Academic Press, 1990, pp. 417-431).

In the present context, the crystallinity of the crystallizablepolymer(s) before the sealing step is substantially uniform across thewhole film(s). However in the final package according to the presentlydisclosed subject matter the crystallinity of the crystallizable polymerin correspondence of the sealing area, i.e. in correspondence of theframe, is higher than the crystallinity of the same polymer in areasother than the sealing area.

“Higher than the crystallinity of the same polymer in areas other thanthe sealing area” means that the difference in the percentage ofcrystallinity of the polymer(s) of the frame with respect to thepolymer(s) of the other parts of the present package is at least 5%preferably higher than 8%, more preferably higher than 10%

As used herein, the phrases “seal layer”, “sealing layer”, “heat seallayer”, and “sealant layer”, refer to an outer layer involved in thesealing of the film to itself, to another film and/or to another articlewhich is not a film.

As used herein the term “peelable”, referred to a film or a sheet meansthat the films sealed to each other provide for a seal which is strongenough to guarantee the hermeticity of the package during its lifecyclebut which can be easily opened by tearing apart by hand the two filmsthat were joined by the seal.

In the presently disclosed subject matter when peelable films are used,each peelable film is capable of forming a seal, under the applicationof heat and/or pressure, to a surface layer of another film of thepackage and the seal is breakable without fracture of the film. A methodof measuring the strength of a peelable seal, also referred to as “peelstrength” is described in ASTM F-88-00. Acceptable peel strength valuesgenerally range from 200 g/25 mm to 850 g/25 mm, from 300 g/25 mm to 830g/25 mm, from 350 g/25 mm to 820 g/25 mm, from 400 g/25 mm to 800 g/25mm.

As used herein, “EVOH” refers to ethylene/vinyl alcohol copolymer. EVOHincludes saponified or hydrolyzed ethylene/vinyl acetate copolymers witha degree of hydrolysis preferably at least 50%, and more preferably, atleast 85%. Preferably, the EVOH comprises from about 28 to about 48 mole% ethylene, more preferably from about 32 to about 44 mole % ethylene.

As used herein, the phrase “machine direction”, herein abbreviated “MD”or longitudinal direction “LD”, refers to a direction “along the length”of the film, i.e., in the direction of the film as the film is formedduring extrusion and/or coating.

As used herein, the phrase “transverse direction”, herein abbreviated“TD”, or crosswise direction refers to a direction across the film,perpendicular to the machine or longitudinal direction.

As used herein, the phrases “orientation ratio” and “stretching ratio”refer to the multiplication product of the extent to which the plasticfilm material is expanded in the two directions perpendicular to oneanother, i.e. the machine direction and the transverse direction. Thus,if a film has been oriented to three times its original size in thelongitudinal direction (3:1) and three times its original size in thetransverse direction (3:1), then the overall film has an orientationratio of 3'3 or 9:1.

As used herein, the phrases “heat-shrinkable,” “heat-shrink,” and thelike, refer to the tendency of the film to shrink upon the applicationof heat, i.e., to contract upon being heated, such that the size of thefilm decreases while the film is in an unrestrained state.

As used herein, the phrases “low heat-shrinkable,” “low heat-shrink” orsimply “low shrink films” and the like, refer to films with a freeshrink in both machine and transversal directions, as measured by ASTM D2732, lower than 10% at 140 ° C., more preferably lower than 5%.

As used herein, the term “polymer” refers to the product of apolymerization reaction, and is inclusive of homo-polymers andco-polymers.

As used herein, the term “homopolymer” is used with reference to apolymer resulting from the polymerization of a single monomer, i.e., apolymer consisting essentially of a single type of mer, i.e., repeatingunit.

As used herein, the term “copolymer” refers to polymers formed by thepolymerization reaction of at least two different monomers. The term“copolymer” is inclusive of terpolymers, random co- or terpolymers,block co- or terpolymers, and graft co- or terpolymers.

As used herein, the term “polyolefin” refers to the polymer orco-polymer resulting from the polymerisation or co-polymerisation ofunsaturated aliphatic, linear or cyclic, straight or branched,hydrocarbon monomers that may be substituted or unsubstituted. Morespecifically, included in the term polyolefin are film-forminghomo-polymers of olefin, co-polymers of olefin, co-polymers of an olefinand an non-olefinic co-monomer co-polymerizable with the olefin, such asvinyl monomers, and the like. Specific examples include polyethylenehomo-polymer, polypropylene homo-polymer, polybutene homo-polymer,ethylene-alpha-olefin co-polymer, propylene-alpha-olefin co-polymer,butene-alpha-olefin co-polymer, ethylene-unsaturated ester co-polymer,ethylene-unsaturated acid co-polymer, (e.g., ethylene-(C₁-C₄)alkylacrylate or methacrylate copolymers, such as for instance ethylene-ethylacrylate co-polymer, ethylene-butyl acrylate co-polymer, ethylene-methylacrylate co-polymer, ethylene-methyl methacrylate co-polymer,ethylene-acrylic acid co-polymer, and ethylene-methacrylic acidco-polymer), ionomer resin, polymethylpentene, etc.

For the purpose of the present description and of the claims whichfollow, except where otherwise indicated, all numbers expressingamounts, quantities, percentages, and so forth, are to be understood asbeing modified in all instances by the term “about”.

BRIEF DESCRIPITION OF DRAWINGS

FIG. 1 is a top view of a the package 1 of an embodiment of thepresently disclosed subject matter, the package being provided with atab (4) for the easy peeling of the film(s).

FIG. 2 a is a cross section view of a first embodiment (1A) of thepackage of FIG. 1.

FIG. 2 b is a cross section view of a second embodiment (1B) of thepackage of FIG. 1.

FIGS. 3A-3B and 3C-3E are other cross-section views of the first (1A)and second embodiment (1B) illustrated in FIGS. 2 a and 2 b.

FIG. 4 is a perspective view of another embodiment of the package ofpresently disclosed subject matter, the package being provided with anaperture (7) allowing vertical displaying of the package.

FIG. 5 is a perspective view of still another embodiment of the packageof presently disclosed subject matter, the package being provided with ahook (8) for vertical display of the package.

FIGS. 6A to E show the profile of some sealing bars suitable for themanufacture of the present package.

FIGS. 7A and 7B illustrate a first method for manufacturing embodiment1A and, respectively, embodiment 1B of a three compartment packageaccording to the presently disclosed subject matter.

FIGS. 8A and 8B illustrate a second method for manufacturing embodiment1A and, respectively, embodiment 1B of a three compartment packageaccording to the presently disclosed subject matter.

FIGS. 9A and 9B illustrate a third method for manufacturing embodiment1A and, respectively, embodiment 1B of a three compartment packageaccording to the presently disclosed subject matter.

DETAILED DESCRIPTION

An embodiment of the presently disclosed subject matter is a tray-lessmulti-compartment package of individually sealed compartments comprising

-   i) two outermost films,-   ii) at least two products in stack,-   iii) at least one internal film interposed between the at least two    products in stack,-   iv) a peripheral circumferential continuous seal which seals the    films in stack together and delimits at least two sealed    compartments in stack, each compartment enclosing at least a product    of said at least two products in stack,    characterized in that the films comprise a crystallizable polymer    and the crystallizable polymer is at least partially crystallized in    correspondence of the sealing area, thus providing a peripheral    circumferential continuous rigid frame.

The present package is a multi-compartment package comprising at leasttwo compartments in stack, each compartment comprising at least aportion or a item of at least one product.

In one embodiment, the present package is a bi-portion packagecomprising two compartments in stack.

In another embodiment the present package is a more than two i.e. tri-or more-portion package comprising more than two compartments in stack.

The total number of compartments depends, inter alia, on the thicknessof the product contained, i.e. the greater is the thickness of theproduct and the lower is the number of compartments of the packageobject of the presently disclosed subject matter.

Internal plastic films are positioned between two subsequent portions ofproduct(s) in the stack and are sealed, for example peelably sealed, toeach other along the frame. In one embodiment, the packages areadvantageously provided with a tab facilitating the opening.

In one embodiment of the multi-compartment package of the presentlydisclosed subject matter (embodiment 1A), only one internal film (6) isinterposed between two adjacent products (2).

In this embodiment (1A), each internal film is in common between twoadjacent compartments (as shown in FIG. 2A for a bi-compartmentspackage) and the removal, one after the other, of the films—i.e. firstan outer film and then the next internal film(s)—provides for the directopening of each compartment.

In the embodiment 1A, in which two adjacent portions or items of same ordifferent products share a single internal plastic film, the package isobtained by alternating the films and the products to be packaged inthis order, up to the desired number of compartments is obtained.

In another embodiment of the multi-compartment package of the presentlydisclosed subject matter (embodiment 1B), as represented in FIG. 2B, twointernal films (6) are interposed between two adjacent products.

In the embodiment 1B, two adjacent portions/items of product(s) arecompletely enclosed by their own films. It is thus possible for the userto detach each single sealed compartment separately but keeping thedifferent portions still packaged. Each single compartment may thus beopened and the product used when and where desired.

A package object of the presently disclosed subject matter generallycomprises from 2 to 20 compartments, for example from 2 to 10, also forexample from 2 to 5.

The number of films required for the package according to the presentlydisclosed subject matter may range from at least n+1 to at most 2n,being n the number of compartments desired.

For the range of compartments from 2 to 10, the package may comprisefrom 3 to 20 films.

According to a first method embodiment of the presently disclosedsubject matter, the films can be hermetically sealed to each other by asingle sealing step at the end of the stacking operation with anappropriate sealing bar which induces the partial crystallization of thesealing area, as represented in FIGS. 7A and 7B.

When suitably shaped, the sealing bar may also thermoform the sealingarea, thus further increasing the rigidity of the frame. In case asealing bar with a thermoforming profile is used, films with lowerorientation ratios may be selected.

In another embodiment, a first sealed compartment, containing theproduct, can be added with alternated product/film or film/product/filmsequences in stack, each new added sequence being sealed progressively,as represented in FIGS. 8A and 8B.

In another embodiment, each compartment comprising two films and aportion of product may be sealed separately and then, the stackedcompartments, sealed/glued together in subsequent steps, as representedin FIGS. 9A and 9B.

The internal plastic film(s) (6) and the outermost plastic films (5) ofthe package according to an embodiment of the presently disclosedsubject matter are sealable and peelable films which allow the easyopening of each compartment and/or the easy detachment of each singlecompartment. The peelable films may comprise a peelable coating or apeelable sealant.

The outermost films and the internal film(s) used in the present packagemay be the same or different.

The outermost films used in a package embodiment of the presentlydisclosed subject matter may be transparent, opaque, colored by pigmentadditives or may have printing thereon or stickers or labels dependingon the desired end use.

One of the two outermost films (5) may be printed; in this case thepackaging machine can house two rolls: one for the printed outermostfilm and the other for the non-printed films of the package.Alternatively, the machine can be provided with an in-line printingsystem, as those commercialised for example by DIGI and a second roll ofmaterial is not needed.

The internal films (6) of the film used in a package embodiment of thepresently disclosed subject matter may be transparent.

The film used in an embodiment of the presently disclosed subject mattermay have a thickness of any of from 100 μm to 5 μm; from 60 μm to 7 μm,and from 40 μm to 10 μm.

The multi-compartment packages allow for a significant reduction ofpackaging material with respect to the weight of the product packagedtherein.

Accordingly, in the present multi-compartments package, the ratiobetween the weight of the packaging material (i.e. the total weight ofthe films) (B) with respect to the total weight of the package (A),calculated as percentage by weight, according to the following formula:(B)/(A)×100, may be lower than 15%, for example, lower than 10%, orlower than 7%.

In the prior art multi-compartment packages—in which a tray or abackboard is present—said ratio is significantly higher, as more than15%, typically more than 20%.

The shape of the frame and that of the (pre)-cut films according to thepresently disclosed subject matter are not limited. For example they canindependently be rectangular, round, oval, triangular or in generalpolygonal or they can follow the shape of the packaged product, thushaving a better pack appearance and becoming more attractive for theconsumer.

The package (1) can have for example a rectangular shape as showed inFIG. 1. Each portion of the product (2) is enclosed in a respectivesealed compartment. The sealing step provides the package with a rigidframe (3) formed by the superimposed and heat-crystallized films.

According to an embodiment of the disclosed subject matter, the packageis advantageously provided with a tab (4) for the easy peeling of thefilm(s).

FIGS. 2 a and 2 b show cross section views along the line A-A of thepackage of FIG. 1 representing two different embodiments (1A and 1B),each one comprising two outer films (5) and one or two internal films(6) respectively. In particular FIG. 2 a illustrates embodiment 1A inwhich only one internal film is interposed between the two products instack while FIG. 2 b illustrates embodiment 1B in which two films areinterposed.

FIGS. 3A-3B and 3C-3E show the mechanism of opening of the packagesillustrated under FIGS. 2A and 2B, in particular, they are cross-sectionviews along the diagonal line B-B of said packages as disclosed in FIG.1.

FIGS. 3A-3B show the opening of the package 1A having a single internalfilm (6) (embodiment A). By pulling one of the outermost films incorrespondence of the tab (4), the respective compartment is directlyopened and the content exposed for prompt use while the remainingpackage is still sealed.

FIGS. 3C-3E show the opening of the package 1B having of two internalfilms (6) (embodiment B). By pulling together one of the outermost films(5) and the adjacent internal film (6) in correspondence of the tab (4),the respective sealed compartment is detached: both the compartments arestill sealed and the content still packaged in independent packages fora later use.

According to a further embodiment of the disclosed subject matter shownin FIG. 4 the package is advantageously designed such as to have anaperture (7) allowing hanging up the package to a vertical display.

According to another embodiment of the disclosed subject matter shown inFIG. 5 the package is advantageously designed such as to have a hook (8)allowing to hang up the package to a vertical display.

Those skilled in the art know tools, equipment and techniques to obtainsuch sealing shapes or hooks or apertures in the package and to provideit with a tab facilitating its opening.

In a package embodiment of the presently disclosed subject matter thecompartments may be filled with a modified atmosphere. Modifiedatmosphere packaging (MAP) is a technique used for prolonging theshelf-life of perishable goods. MAP packages according to the presentlydisclosed subject matter may be manufactured following methods known inthe art, such as “gas-flushing” and “compensated vacuum”.

In another embodiment, the compartments of the present multi-compartmentpackage are under vacuum, thus advantageously extending the shelf-lifeof the enclosed perishable food products (vacuum packaging). In thatcase, air is removed from the compartments before sealing, then thecompartments are hermetically sealed without any gas flushing orcompensation.

In a package embodiment of the presently disclosed subject matter, thefilms comprise crystallizable polymer(s), namely polymer(s),homopolymer(s), copolymer(s), blends, compounded formulations orrecyclates, resins which can crystallize at the sealing conditionsadopted during the sealing step, i.e. upon heating and/or compression.

Crystallizable polymers are for instance crystallizable polypropylene(s)homo- or copolymers, high density polyethylenes (HDPEs), medium densitypolyethylenes (MDPEs), polyesters, biodegradable polyesters such aspolylactic acids (PLAs), polyamides such as PAG, preferably added withnucleating agents, polystyrenes (PS), more preferably crystallizablepolyesters, and their blends.

The amount of the crystallizable polymer in the films of the presentpackage with respect to the total weight of the films is at least 30% byweight, for example any of at least 50%, 60%, 70%, 80%, 90% or 95%.

The package according to an embodiment the presently disclosed subjectmatter comprises polyester-based films each one having the samethickness and composition. In alternative, the films of the presentpackage may be of different thickness and/or composition.

The crystallizable polyester resins that may be used for the presentlydisclosed subject matter are able to crystallize upon heating, i.e. attemperatures—typically ranging from 140° C. to 220° C.—generally adoptedin the sealing stage of the manufacturing process.

Crystallizable polyester resins preferably used for the presentlydisclosed subject matter are able to crystallize under heating and/orunder compression—e.g. by setting the sealing machine at temperaturestypically ranging from 140° C. to 220° C., preferably 170 to 200° C.and/or at a pressure generally ranging from 2 to 8 bar, preferably 4 to7 bar—temperature and pressure settings generally adopted in the sealingstage of the manufacturing process.

The films are mono- or multilayer films, and may be peelable films, eachcomprising at least 30% by weight, with respect to the total weight ofthe film, of a crystallizable polyester resin preferably at least 50%,60%, 70%, 80%, 90% or 95%.

In the film suitable for the package according to an embodiment of thepresently disclosed subject matter, the percentage of crystallinity ofthe crystallizable polymer, for example of the crystallizable polyestersand/or copolyesters, will be higher than 15%, for example higher thanany of 20%, 25%, and 30% in correspondence of the sealing area, afterthe sealing step.

The percentage of crystallinity of the polyesters and co-polyesterssuitable for embodiments of the disclosed subject matter is evaluated byDifferential Scanning Calorimetry (DSC), as known in the art (see B.Wunderlich, Thermal Analysis, Academic Press, 1990, pp. 417-431).

Polyesters are polymers containing ester groups in their backbone chainobtained from the reaction of a diol with a diacid. In homopolyestersonly one species of diol and of diacid are employed, while inco-polyesters at least one of the carboxylic acids or of the diols isused in combination of at least two species.

Suitable crystallizable polyesters for the films of the present packageinclude homo-polyesters, such as poly(ethylene terephthalate),poly(ethylene 2,6-naphthalate), poly(1,2-propylene terephthalate),poly(ethylene 2,5-dimethyl-terephthalate), poly(butylene terephthalate),poly(ethylene isophthalate), poly(ethylene 5-t-butyl-isophthalate),poly(butylene 2,6-naphthalate), and the like homopolymers, andco-polyesters where the diacid component is still mainly based onaromatic diacids such as terephthalic acid, isophthalic acid, alkylsubstituted-terephtahlic acid, alkyl-substituted isophthalic acid.

Suitable crystallizable homo-polyester and co-polyester resins aretypically characterized by a high melting point (Tm), such as a Tmhigher than 220° C., preferably higher than 230° C.

Specific examples include Eastapak Copolyester 9921 sold by Eastman andRamapet N180 sold by Indorama.

Crystallizable biodegradable polyester resins can also be used. Examplesof crystallizable biodegradable polyesters are: polyglycolide (PGA) andits copolymers with caprolactone, lactide or trimethylene carbonate,polylactide (PLA), poly(lactide-co-glycolide) (PLGA), Poly(butylenesuccinate) (PBS) and poly(ethylene succinate), poly(butyleneadipate-co-terephtalate (PBAT). A suitable PLA is commercialized forexample under the trade name of NatureWorks® by CargillDow. A suitablePBAT is sold as Ecoflex® by BASF, Eastar Bio® by Eastman Chemical,Origo-Bi® by Novamont.

A multi-compartment package according to the presently disclosed subjectmatter substantially made of crystallizable biodegradable polyester(s)will be even more eco-friendly.

Polyesteramides may also be used such as those commercialized by Bayerunder the trade name BAK®.

The crystallizable polymers films suitable for the package according toan embodiment of the presently disclosed subject matter may consist oftwo layers, a base layer and a sealing layer.

The crystallizable polymers may be crystallizable polyester resins.Suitable crystallizable polyester resins for the base layer are thosedescribed before.

In an embodiment, the crystallizable polyester resin of the base layeris blended with an amorphous polyester resin. Said amorphous polyesteris characterized by a Tg value lower than 115° C., preferably lower than95° C., even more preferably lower than 85° C.

The amount of said amorphous polyester in the base layer of the film ofthe present package is generally at most 70% by weight with respect tothe total weight of the base layer, for example at most any of 50% and40% by weight.

Suitable amorphous polyester resins are those deriving from an aliphaticdiol and/or a cycloaliphatic diol with one or more dicarboxylic acids,preferably an aromatic dicarboxylic acid. Preferred amorphous polyestersare copolyesters of terephthalic acid with an aliphatic diol and acycloaliphatic diol, particularly ethylene glycol and1,4-dicyclohexanedimethanol. The preferred molar ratios of thecycloaliphatic dial to the aliphatic diol are in the range from 10:90 to60:40, preferably in the range from 20:80 to 40:60, more preferably from30:70 to 35:65. Specific examples of particularly preferred amorphouspolyester are PETG Eastar® 6763, sold by Eastman (glass transitiontemperature 81° C., density 1.27 g/cc) and Embrace sold by EastmanChemical, (glass transition temperature 70.6° C., density 1.32 g/cc).

In another embodiment, the whole film or, if present, said base layerwill comprise one or more suitable crystallizable home- and/orco-polyesters blended with up to preferably about 10% of a masterbatchcontaining conventional additives dispersed in a (co)polyester matrix,additives known in the art as nucleating agents, which favor thecrystallization process during the sealing step.

Suitable nucleating agents are for instance those listed in Table 1 ofthe Literature Review by H. Zhou available at the internet addresswww.crd.ge.com as 98CRD138. Particularly preferred nucleating agents areinorganic compounds such as talc, silicate, clay, titanium dioxide, andthe like. These compounds may be used in an amount lower than 5% byweight, typically in an amount of 1-2% by weight on the total weight ofthe film or base layer. Other preferred nucleating agents are certaincompatible polymers such as fluoropolymers (PTFE) that can be blendedwith the polyester of said film or layer (a) in an amount of up to e.g.5-8% by weight.

Examples of nucleating agents particularly suitable for crystallizingpolyesters which can be used in the present application are: (i) alkalimetal salts of organic acids, e.g. carboxylic acid; sodium, lithium,potassium benzoates (see D. Garcia, Heterogeneous nucleation of PET, J.of Polymer Science—Polymer physics edition, Vol 22, 2063-2072, 1984 andR. Legras, C. Bailly, M. Daumerie, V. Zichy and others, Chemicalnucleation, a new concept applied to mechanism of action of organic acidsalts on the crystallization of PET and bisphenol-A-polycarbonate,Polymer, Vol 25, 835-844, 1984) or sodium salts of substituted benzoicacids which contain at least one nitro, halogen, hydroxyl, phenyl oroxyphenyl substituent, and salts of alkali metals including phenolic,phosphonic, phosphinic and sulfonic (see EP0021 648); (ii) lithiumand/or sodium salts of aliphatic, cycloaliphatic, aromatic carboxylicacids or heterocyclic polycarboxilic acids, containing up to 20 carbonatoms (see U.S. Pat. No. 3,761,450); (iii) DBS-dibenzylidene sorbitol(see J. of Applied Polymer Science, Vol 36, 387-402, 1988); (iv)trygliceride oil and triglyceride oil in combination with/or chemicallybonding to organic acid metal salts (see U.S. Pat. No. 5,356,972).Nucleating agent that may be used in the presently disclosed subjectmatter are commercially available as Tna 5471 by Sukano, Elvaloy PTW andElvaloy AC by Dupont, Hyperform HPN series by Milliken.

Examples of nucleating agent that can be used in the presently disclosedsubject matter suitable for crystallizing polypropylenes are thecompounds supplied by Milliken under the trade name of Millad.

The amount of nucleating agent generally depends on the type of polymerused. According to the conventional practice, the nucleating agent isgenerally used in an amount of from 2% to 5%, more preferably from 2.5%to 4%, even more preferably of about 3%.

Preferably the nucleating agents have a particle size not higher than 10microns.

The base layer may have a thickness between about 10 and 90 μm, morepreferably between about 15 and 60 μm, even more preferably betweenabout 20 and 35 μm.

The heat-sealable layer can comprise at least a first amorphouspolyester resin and optionally a further polyester resin.

The amorphous polyester is characterized by a Tg value lower than 115°C., for example lower than 95° C. or lower than 85° C. Suitableamorphous polyester resins are those deriving from an aliphatic diol anda cycloaliphatic dial with one or more dicarboxylic acids, for examplean aromatic dicarboxylic acid. Amorphous polyesters may be copolyestersof terephthalic acid with an aliphatic diol and a cycloaliphatic diol,particularly ethylene glycol and 1,4-dicyclohexanedimethanol. Theexemplary molar ratios of the cycloaliphatic diol to the aliphatic diolare in the range from 10:90 to 60:40, for example in the range from20:80 to 40:60, or from 30:70 to 35:65. Specific examples of amorphouspolyester are PETG Eastar® 6763, sold by Eastman (glass transitiontemperature 81° C., density 1.27 Wee) and Embrace sold by EastmanChemical, (glass transition temperature 70.6° C., density 1.32 g/cc).

A blend of two or more amorphous polyesters is also suitable for theheat sealable layer of the films of the present package.

Suitable further polyesters can be added in the sealant layer. Suchpolyester can be those deriving from an aliphatic diol, preferablyethylene glycol and one or more aromatic dicarboxylic acid, preferablyterephthalic acid.

Polyethylene terephthalate and its copolyesters may be used. Specificexamples include Eastapak Copolyester 9921 sold by Eastman and RamapetN180 sold by Indorama.

The amount of the first amorphous polyester in the heat-sealable layerof the film of the presently disclosed package may be at least 30% byweight with respect to the total weight of the heat-sealable layer, forexample at least 50% by weight, or at least 60% by weight.

The amount of the further polyester in the heat-sealable layer of thefilm of the present package is generally at most 70% by weight withrespect to the total weight of the heat-sealable, for example at most50% or at most 30% by weight.

In an embodiment, the internal film(s) (6) and the outermost films (5)of the package according to an embodiment of the presently disclosedsubject matter are made of peelable films thus allowing the easy openingof each compartment and/or its separation from the others.

For example, the films may be peelable crystallizable polyester-basedfilms.

Peelability can be imparted to the films by admixing further resins inthe sealant layer, usually from 3 to 40% by weight, more frequently 10to 25% by weight of an appropriate thermoplastic resin. Suitablethermoplastic resins that contribute to lowering the sealing strength ofa polyester sealant layer of a film are polyethylens, polyamides,polystyrenes, in particular styrene-butadiene block copolymers,ionomers, ethylene/unsaturated carboxylic acid copolymers, likeethylene/(meth)acrylic acid copolymers and ethylene/cyclic olefincopolymers, like ethylene/norbornene copolymers. These resins have lowcompatibility with the polyester resin layer and the resulting phaseseparation confers the desired peelability. Specific examples arePRIMACOR 3440 by Dow, an ethylene/acrylic acid copolymer and Bynel 4104by Du Pont de Nemours, an anhydride-modified linear low-densitypolyethylene (LLDPE).

The thickness of the heat-sealable layer is generally between about 5and 40% of the thickness of the base layer. The heat-sealable layer mayhave a thickness of up to about 25 μm, for example up to about 15 μm, orbetween about 0.5 and 10 μm, or between about 0.5 and 7 μm.

Additional layers can be present in the film of the presently disclosedsubject matter.

For example, an outer layer can be present, having a thickness up toabout 25 μm, for example up to about 15 μm, or between about 0.5 μm and10 μm, or between about 0.5 μm and 7 μm. The outer layer is theoutermost layer of the structure.

The polyester resins suitable for the composition of the outermost layermay be selected among the list of crystallizable polyester resinsreported above.

In an embodiment, the crystallizable polyester films useful for thepackage according to the first object of the presently disclosed subjectmatter comprise at least two layers: the sealant and the base layer.

In an embodiment, the crystallizable polyester films comprise at leastthree layers: the sealant, the base layer and the outer layer.

In an embodiment, the same crystallizable polyester resin, either aloneor in blend, is used for the base and the outer layer. Preferred resinsare Eastapak Copolyester 9921 sold by Eastman and Ramapet N180 sold byIndorama.

In an embodiment, the same amorphous polyester resin is used in the baselayer and in the sealant layer. Preferred resins are PETG Eastar® 6763sold by Eastman and Embrace sold by Eastman Chemical.

In case of two or three layers films, the crystallizable polyester maybe present at a percentage in weight ranging from 50 to 70% with respectto the total weight of the film and the amorphous polyester may bepresent at a percentage in weight ranging from 25 to 35% with respect tothe total weight of the film.

The films of the present package can further comprise a gas-barrierlayer, which may be medium or high barrier to gases, especially tooxygen, depending on the product to be packaged.

As used herein the term “medium barrier film” refers to a film having anoxygen transmission rate (OTR) lower than 200 cc/sqm/day, preferablylower than 100 cc/sqm/day at 100% RH and 23° C.

The multilayer film may comprise at least a high gas-barrier layer andcan exhibit an oxygen transmission rate (OTR) lower than 50, forexample, lower than 30, or lower than 20 cc/m²day bar at 23° C. and 100%relative humidity.

The OTR of plastic films can be measured following ASTM D3985.

Well-known gas-barrier resins and their blends suitable for the barrierfilms include, for example, ethylene-vinyl alcohol copolymers (EVOH),polyamides and acrylonitrile-based copolymers. Once the gas-barrierresin has been selected, its thickness will be set to provide for thedesired permeability properties.

In the film, tie layers, to improve interlayer adhesion, may be present.Tie layers may be disposed between the respective layers in case where asufficient adhesion is not ensured between adjacent layers. The adhesiveresin may preferably comprise one or more polyolefins, one or moremodified polyolefins or a blend of the above. Specific, not limitative,examples thereof may include: ethylene-vinyl acetate copolymers,ethylene-(meth)acrylate copolymers, ethylene-alpha-olefin copolymers,any of the above modified with carboxylic or preferably anhydridefunctionalities, elastomers, and a blend of these resins.

One or more of the layers of the film of the presently disclosed subjectmatter may contain any of the additives conventionally employed in themanufacture of polymeric films. Thus, agents such as pigments,lubricants, anti-oxidants, radical scavengers, oxygen scavengers, UVabsorbers, odour absorbers, thermal stabilisers, anti-blocking agents,surface active agents, slip aids, optical brighteners, gloss improvers,viscosity modifiers may be incorporated as appropriate. In particular,to improve the processing of the film in high speed packaging equipmentslip and/or anti-blocking agents may be added to one or both of theouter layers. The additives may be added in the form of a concentrate ina polyester carrier resin. As an alternative slip agents may be added bycoating, for instance by plasma coating or by spraying (e.g. with a Wekoequipment). The amount of additive is typically in the order of 0.2 to5% by weight of the total weight of the layer.

In another embodiment, the films (5 and/or 6) of the present package canbe mono-layer films; in this case, suitable crystallizable polyesterresins, optionally blended to amorphous polyesters, are the same—both interms of kind and percentages—as the ones for the base layer listedabove.

The monolayers films suitable for the present packages are sealable; andthe monolayers films may also be peelable.

In order to impart the required peelability and sealability, the filmscan be coated, either during or after their manufacturing, with wellknown suitable compositions. Typical coating composition and method arefor examples described in WO9619333, WO0154886, WO2011083342. Thecoating composition can be applied to the film by any suitableconventional technique, for example by spraying, dip coating, rollcoating, bead coating, reverse roller coating or slot coating,impregnation.

The grammage of the applied coating layer is typically in the range from0.1 to 5.0 g/m², for example, any of from 0.3 to 3.0 g/m², and from 0.5to 2.0 g/m². The thickness of the coating layer is typically in therange from 0.3 to 10 μm, for example, from 0.5 to 5.0 μm or from 1.0 to2.0 μm.

The coating can be applied onto one surface of the film or onto both thesurfaces. For films coated on both their surfaces, the same ranges ofgrammage and thickness listed above are applicable to each coatinglayer.

Before the deposition of the coating layer onto the film, the surface tobe coated may advantageously be subjected to a chemical or physicaltreatment in order to improve the bond between that surface and theapplied coating layer. One of the preferred treatments is to expose thesurface to be coated to a high voltage electrical stress accompanied bycorona discharge. Alternatively, the substrate may be pre-treated withan agent known in the art to have a solvent or swelling action on thefilm. For example, for polyester films, suitable agents includehalogenated phenols dissolved in an organic solvent, as a solution ofp-chloro-m-cresol, 2,4-dichlorophenol, 2,4,5- or 2,4,6-trichlorophenolor 4-chlororesorcinol in acetone or methanol. Such coatings can also beapplied to a multilayer film. In this case there is no need to impartpeelability to the film by adding—in the sealant layers—resins havinglow compatibility with the resin of the sealant layer.

The films of the presently disclosed package may be low-shrink films asdefined above. These films have no or negligible shrink at temperaturesbelow 140° C. The shrink (in each direction) is generally at most 15% attemperatures below 100° C., below 120° C., and even below 140° C.

Usually, in case of polyester based films, the shrink (in eachdirection) does not exceed 15% over the common heat-sealing temperaturerange of polyester films, namely in the range of from 140 to 200° C. Theshrink generally does not exceed 15% (in each direction) at 180° C., at160° C., and even at 150° C.

Depending on the resins employed and on the particular finalapplication, these films can be manufactured by coextrusion, extrusioncoating, and/or lamination of preformed cast films, followed by mono- orbiaxial orientation and, optionally, by an annealing or heat-settingstep, or they may be prepared by lamination of preformed films of whichat least part of them have been mono- or bi-axially oriented.

Typically, coextrusion equipment are used, where each resin is extrudedthrough an extruder and all the layers are joined into the extrusiondie. Typically, for polyester films, flat die is used.

The film may be oriented. A tubular or flat film orientation process canbe used to produce a biaxially oriented film. The flat film may beoriented with a tenterframe apparatus. In a tubular process, also knownas “double bubble” process, simultaneous biaxial orientation is obtainedby coextruding thermoplastic resins in a tube shape which issubsequently quenched, reheated and then expanded by internal gaspressure to induce transverse orientation, and withdrawn at a rate whichwill induce longitudinal orientation. An example of equipment suitablefor this technique is disclosed by U.S. Pat. No. 4,841,605. Inalternative, a triple-bubble orientation process may also be used, insuch a case a final relaxation or annealing step being included, asknown in the art. Another possible tubular process suitable formanufacturing the films of the present package is the “hot blown”process.

In a flat film process, the film-forming thermoplastic resins areextruded through a T-die and rapidly quenched upon a chill roll toensure that the resins are quenched to the amorphous state. In order toimprove the adhesion of the film on the chill roll electrostatic pinningcan be used, as known in the art and as described in U.S. Pat. No.5,494,619.

Orientation is then, optionally, effected by flat stretching,simultaneously or sequentially, the quenched extrudate at a temperatureabove the glass transition temperature of the thermoplastic resins.

In the sequential flat orientation method a flat, quenched extrudate isfirstly oriented in one direction, usually the longitudinal direction,i.e. the forward direction through the film stretching machine, and thenin the transverse direction. Longitudinal stretching of the extrudate isconveniently carried out over a set of rotating rolls (MDO), whichrotate at different speeds. At least one of the first pairs of rolls isheated, for example by inner circulation of hot oil. Transversestretching is usually carried out in a tenter apparatus (TDO), whichcomprises a certain number of heating zones and suitable stretchingmeans.

To manufacture the multilayer films useful for the present package, thepolymers for the various layers are fed to separate extruders. The meltsare extruded through a multilayer T-die and quenched over a chill roll.Longitudinal stretching (MDO) of the extrudate is conveniently carriedout at a temperature range from 60 to 120° C., preferably from 70 to100° C. In the transverse stretching (TDO), the temperatures of the filmare in the range from 90° C. (preheating zone) to 130° C. (stretchingzone), preferably from 90° C. (preheating zone) to 110° C. (stretchingzone). The longitudinal stretching ratio is in the range from 2.0:1 to5.0:1, preferably from 2.3:1 to 4.8:1. The transverse stretching ratiois generally in the range from 2.4:1 to 6.0:1, preferably from 2.6:1 to5.5:1.

In the simultaneous flat orientation method a flat, quenched extrudateis simultaneously oriented in both the longitudinal and in thetransverse direction through a simultaneous tenter apparatus.

The extrudate is fed to the pre-heating zone of a simultaneous tenterapparatus, with or without a prior passage through an IR heated oven.The temperature of the oven in said pre-heating zone, the length thereofand the time spent by the traveling web in said zone (i. e. the webspeed) can suitably be varied in order to bring the film up to thedesired temperature for bi-axial orientation. In a preferred embodimentthe orientation temperature is comprised between about 90° C. and about140° C. and the temperature of the pre-heating zone is kept betweenabout 90° C. and about 150° C. In said pre-heating zone the film isclipped but it is not yet stretched. Thereafter, the resulting hot,optionally irradiated, and clipped film is directed to the stretchingzone of the simultaneous tenter. Any simultaneous stretching means canbe used in said zone. Preferably however the clips are propelledthroughout the opposed loops of the tenter frame by means of a linearsynchronous motor. A suitable line for simultaneous stretching withlinear motor technology has been designed by Bruckner GmbH andadvertised as LISIM line. An alternative line for simultaneousstretching of the extruded flat tape is the Andritz line, based on apantograph, equipped with two separated monorails on each side of theorientation unit. The configuration of the tenter can be varieddepending on the stretching ratios desired.

The temperature in the stretching zone is kept close to the selectedorientation temperature. In case, annealing is carried out at atemperature of from 130 to 220° C., the temperature depending on thedesired shrink. Subsequently, the film is wound up in a customarymanner.

Following the optional annealing or heat-setting step the film istransferred to a cooling zone where generally air, either cooled or keptat the ambient temperature, is employed to cool down the film. Thetemperature of said cooling zone is therefore typically comprisedbetween about 20° C. and about 40° C. At the end of the line, the edgesof the film, grasped by the clips and not oriented, are trimmed off andthe obtained bi-axially oriented, heat-shrinkable or heat-set film isthen wound up, with or without prior slitting of the film web to thesuitable width.

A second embodiment of the presently disclosed subject matter is amethod for manufacturing the multi-compartment package of the presentlydisclosed subject matter, such a method comprising the steps of:

-   i) providing two outermost and at least one internal, optionally    pre-cut, crystallizable films;-   ii) providing at least two products to be packaged;-   iii) stacking an outermost film, the product(s), the internal    film(s)—alternating the products and the internal film(s)—and the    other outermost film, up to the desired number of compartments is    obtained;-   iv) sealing and simultaneously crystallizing the stack of films    along a peripheral circumferential continuous sealing area thus    providing a peripheral circumferential continuous rigid frame, and-   v) optionally, simultaneously or afterwards, cutting the stack of    films all around all around outside the frame thus providing the    multi-compartment package;    or, alternatively the steps of:-   a) providing two outermost and at least one internal, optionally    pre-cut, crystallizable films;-   b) providing at least two products to be packaged;-   c) placing in stack an outermost film, a product and an internal    film;-   d) sealing and simultaneously crystallizing the stack of films along    a peripheral circumferential continuous sealing area thus providing    a peripheral circumferential continuous rigid frame;-   e) optionally, simultaneously or afterwards, cutting the stack of    films all around outside the frame thus providing the first    compartment of the package;-   f) placing a stack of “a product/a film” or of “a film/a product/a    film”, onto the compartment formed in steps c) to e);-   g) repeating point d) to f) for each new compartment up to the    desired number of compartments is obtained, thus providing the    multi-compartment package or, alternatively the steps of:-   A) providing two outermost and at least two internal, optionally    pre-cut, crystallizable films;-   B) providing at least two products to be packaged;-   C) placing in stack a film, a product and a film;-   D) sealing and simultaneously crystallizing the stack of films along    a peripheral circumferential continuous sealing area thus providing    a peripheral circumferential continuous rigid frame;-   E) optionally, simultaneously or afterwards, cutting the stack of    films all around outside the frame thus providing the first    compartment of the package;-   F) manufacturing at least another compartment following steps A to    E;-   G) stacking the first and the new compartment(s), optionally placing    a product in between;-   H) sealing or gluing together the first and the other new    compartment(s), simultaneously or one after the other if more than    two, up to the desired number of compartments is obtained, thus    providing the multi-compartment package.

Independently of the method used, a partial crystallization of the filmsalong the sealing area occurs during the sealing operation thusproviding the rigid frame.

FIGS. 7A and 7B illustrate methods for manufacturing embodiment 1A and,respectively, embodiment 1B of a three compartment package according tothe presently disclosed subject matter. In this scheme for the sake ofclarity, only steps iii) (stacking) and iv) (sealing) of the presentmanufacturing process are represented, being the other steps of i)providing the films, optionally pre-cut, ii) providing the products and,v) optionally cutting the stack of films to provide the final packageare also meant to be included.

The first embodiment of manufacturing the present package disclosedabove may be advantageously used.

According to this first embodiment, the outermost films, the internalfilm(s) and the products are alternated and stacked up to the desirednumber of compartments is obtained, then all the films in stack aresealed and cut. The films may also be pre-cut before the stacking step;in this case the further cutting step can be optional. During thesealing step, the films are heat crystallized thus forming the rigidframe of the package.

In embodiment 1A of the present package only one internal film ispresent. Accordingly, in the manufacturing process of this package, thesequence of films and products to be stacked is: “film/(product/film):where “n” is an integer number higher than 1 representing the number ofcompartments desired.

In a two-compartments package according to embodiment 1A (n=2) thesequence of films and products in stack is:“film/product/film/product/film”, wherein the products and the films canbe the same or different.

In a more than two-compartments package (n>2) according to embodiment1A, the sequence of films and products in stack is: “film/(product/film)n>2”, wherein the products and the films can be the same or different.

In embodiment 1A of the present package two adjacent compartments sharethe same internal film and the compartments are opened preferably oneafter the other in the same order they have in the package.

In another embodiment (1B), each compartment has its own internal films,namely there are two internal films between each couple of adjacentproducts in stack.

In the manufacturing process of the package according to embodiment 1B,the sequence of films and products to be stacked is:

“(film/product/film)_(n)” where “n” is an integer number higher than 1representing the number of compartments desired.

In a two-compartment package according to embodiment 1B (n=2) thesequence of films and products in stack is:“film/product/film/film/product/film”, wherein the products and thefilms can be the same or different.

In case of n compartments, where n is higher than 2, the sequence offilms and products in stack is: “(film/product/film)n>2”

In embodiment 1B two adjacent products will be separated by two internalfilms. This embodiment 1B allows the consumer to detach sealedcompartments, while keeping each portion still packaged, and to openthem later and independently.

To facilitate the detachment of each single sealed compartment from theothers, the bonding between adjacent compartments may be suitablyweakened, for instance by imparting higher peel properties to thesurfaces of the films directly involved in said bonding.

In an advantageous embodiment 1B, the bonding between the films ofadjacent compartments (inter-compartments bonding) will be weaker thanthe bonding within the films of each compartment (intra-compartmentbonding) thus allowing a clean detachment of each sealed compartment andavoiding untimely opening of the same. A different bonding may also beobtained for instance by selecting different means for intra- andinter-compartments bonding, such as sealing vs gluing etc.

In such a case, the manufacturing process may be according to a thirdembodiment of said process. If the strength of the bonding imparted bygluing is lower than those conferred by sealing, the detachment of eachstill sealed compartment will be facilitated.

According to a second variant of a manufacturing process of the presentmulti-compartment package, represented in FIGS. 8A and 8B, a firstcompartment is made by stacking in sequence a film, a product and a filmand by sealing the stacked films; afterwards, a new stack of a productand one/two film(s)—arranged as “product/film” for manufacturing thepackage of embodiment 1A or as “film/product/film” for embodiment 1B—isadded onto the first compartment previously manufactured and the thusformed stack of films and products are sent again to the sealingstation, were the films are sealed, crystallized and cut if needed.

Each new product to be packaged is added—covered by one or sandwichedbetween two film(s)—to the package already made in the previous steps,up to the desired number of compartments is obtained. This stepwiseprocess has the advantage of repeating the sealing/crystallizing stepseveral times thus providing the multi-compartment package with a morerigid frame. A higher rigidity may be advantageous in case of heavier ormore delicate products. This process may also be useful when there isthe need to alternate different products.

However, in case of a package with a higher number of compartments (i.e.more than 3) it may be advantageous to replace one or more of thesealing steps d) of the present second method with one or more gluingsteps as the rigidity conferred by the sealing steps already performedmay suffice for the final use of the package. Gluing steps may becarried out, for instance, as described below for the thirdmanufacturing method.

FIGS. 8A and 8B illustrate a second method for manufacturing embodiment1A and, respectively, embodiment 1B of a three compartment package.

In this scheme for the sake of clarity, only steps c and f) (stacking),d) (sealing) and g) (their repetition) of the present manufacturingprocess are represented, being the other steps of a) providing thefilms, optionally pre-cut, b) providing the products and, e) optionallycutting the stack of films to provide the final package are also meantto be included.

For the method of this second embodiment, the sequence of components inthe final package is “film/(product/film)_(n)” for embodiment 1A or“(film/product/film)_(n)” for embodiment 1B being n the total number ofcompartments (n>1).

In a third variant of the of the present manufacturing method, two ormore pre-made compartments, are joined together by sealing or, inalternative, by gluing.

FIGS. 9A and 9B illustrate this third method for manufacturingembodiment 1A and, respectively, embodiment 1B of a three compartmentpackage according to the presently disclosed subject matter.

In this scheme for the sake of clarity, only steps C) (stacking a film,a product and a film), D) (sealing), G) (stacking each new compartmentonto the previous one(s), optionally placing a product in between) andH) (sealing or gluing) of the present manufacturing process arerepresented, being the other steps of A) (providing the films,optionally pre-cut), B) (providing the products), E) (optionally cuttingthe stack of films), F) (manufacturing at least another compartment), toprovide the final package are also meant to be included.

In the present method, the pre-made compartments may be sealed or gluedsimultaneously in stack or added and sealed /glued stepwise, one afterthe other.

If the pre-made compartments are stacked or added without any furtherproduct interposition, a multi-compartment package according toembodiment 1B will be obtained.

In alternative, if a product is inserted between each couple of adjacentcompartments, a multi-compartment package according to embodiment 1A maybe manufactured. In this case, especially for food products, thecompartments are advantageously joined together by sealing rather thanby gluing to prevent undesired product contaminations.

As used herein the term “gluing” refers to placing a discrete orcontinuous layer of an adhesive, preferably along the frame, onto atleast one of the facing surfaces of two adjacent compartments to beglued and joining the compartments by applying a pressure sufficient tolet them adhere to each other.

The term “adhesive” is used herein to indicate any material that enablesthe adhesion of two compartments to each other.

The thickness of the layer of adhesive can be comprised between 0.2 and10 μm, for example from 0.5 to 5 μm, or from 1 to 3 μm.

The adhesives suitable for joining the compartments according to thisembodiment are well known in the art. For instance suitable adhesivesmay be the aqueous dispersions sold by Paramelt under the trade name ofAquaseal or the compositions described in WO 2005/021638 (e.g., U.S.Pat. Nos. 7,803,865; 8,193,275; and 8,232,336) or in WO 2009/055275(e.g., U.S. Pat. No. 8,475,878) under the code DPOD 8501. Each of thesepatents is incorporated herein in its entirety by reference.

The so called “cold seal” materials may be used, as those supplied forexample by Fabrico (division of EIS), Basic Adhesive, Printpack Inc.

Adhesive materials known as “hot melt pressure sensitive adhesives(HMPSA),” are also suitable for the disclosed subject matter, forexample those commercialized by Bostik and Henkel

Systems for applying hot melt adhesives are e.g. hot melt handguns, rollcoaters, benchtop extruders, automatic extrusion, fiberization system.

Various adhesive coatings are described, for example, in WO 2005/021638and WO 2011/083342.

The adhesive layer has to be deposited onto the external surfaces of thecompartments to be joined, for example, along the frame.

In case of cold seal, this can be done on both the surfaces to bejoined.

The layer of adhesive can be discrete or continuous along the frame.

The adhesive may be applied along the frame as described, for instance,in WO 2011/083342.

In a variant of this third embodiment for manufacturingmulti-compartments packages according to embodiment 1B, the pre-madecompartments may be joined by gluing. Advantageously it is possible toselect gluing conditions and adhesives in such a way to obtaininter-compartments bonding weaker than the intra-compartment bonding,thus facilitating the removal of each still sealed compartment.

The methods of manufacturing the present package described above may beimplemented with suitable packaging machines such as tray lidding andthermoforming machines with contour sealing and cutting.

Specific example of suitable machines that can be adapted to run theprocess of the present disclosed subject matter include for instanceMultivac 400 and Multivac T550 by Multivac Sep. GmbH, Mondini E380, E390or E590 or Trave by Mondini S.pA, Ross A20 or Ross 545 by Ross-Reiser,Meca-2002 or Meca-2003 by Mecaplastic, the tray lidding machinesmanufactured by Sealpac, Ulma Taurus and Ulma Scorpius supplied by UlmaPackaging, Ishida QX and the like machines.

Thermoforming machines are suitable for the process described above,without significant modifications. Especially in case of food productsto be packaged, a slicer can be advantageously added in order to slicethe product.

In one embodiment, an additional conveyor carrying the weightedproduct(s) to the stacking zone can also be advantageously provided.Afterwards, the product(s) can be positioned onto the belt carrying thefilms and the stacking of films and products is repeated up to thedesired number of compartments is achieved. Then, the stacked films andproducts are carried to the thermoforming zone, where sealing,crystallization and cutting occur.

In another embodiment, a pre-cutting unit to pre-cut the film isadvantageously provided in order to cut the films from the roll at ameasure suitable for the package. Some existing tray lidding packaginglines supplied e.g by Risco and Vemag are already equipped withpre-cutting unit, for instance those for the packaging of minced meat.

In another embodiment, the cutting of the package is performed after thesealing step. In another embodiment, the cutting of the package isperformed at the same time of the sealing step.

In case a tab for easy opening is desired, the cutting blade will beshaped in such a way to provide the tab when cutting the films, as knownto the person skilled in the art.

In case the films are of different composition or the outermost filmsare printed, the packaging machine may provide the housing for more thanone roll of films.

Sealing may be carried out by means of a heated frame by setting themachine at temperatures, in case of polyester based films, of from 140to 220° C., for example, from 170 to 200° C. and at a pressure of from 2to 8 bar, for example, from 4 to 7 bar. Sealing times are typically inthe order of 0.01 to 2.0 seconds, for example, from 0.5 to 1.0 seconds.

However, other known sealing techniques such as ultrasonic welding mayalso be used, providing that they are able to induce an at least partialcrystallization of the films along the sealing area.

In case of HDPE or polypropylene based films, lower sealing temperaturesare generally selected, for instance in the range of from 120 to 180° C.providing that the selected temperatures are suitable for at leastpartially crystallizing the polymers under the operational sealingconditions.

The sealing bar can have different shapes such as to obtain, forexample, a flat or a thermoformed area where the films are sealed toeach other, the thermoformed option being preferred, as it provides fora higher rigidity of the frame. Such sealing bars are commercialized bypackaging machine suppliers.

FIGS. 6A-E illustrate cross-sections of some suitable sealing bars. Inparticular the sealing bar profile can be flat or rounded. The sealingbar may have a thermoforming profile, as shown in FIGS. 6A or 6E, namelythe bar will seal the films along the sealing area while imparting adesired shape to the at least partially crystallized frame, furtherincreasing its rigidity. For instance, according to the profile of thesealing bars illustrated in FIG. 6A or 6E, there will be areas where,upon sealing, a higher pressure will be applied onto the stacked filmsand, correspondingly, a higher degree of crystallization will beimparted to the frame.

Typically, the width of the sealing area of the package, i.e. the widthof the frame, is from 1 mm to 20 mm, for example, from 2 mm to 15 mm, orfrom 3 to 10 mm.

The dimensions, in terms of area extension, of the packaged product arenot limited, provided that they do not exceed the dimensions of the cutfilms, and allow a suitable frame to be formed.

The film dimensions can be adjusted according to the product dimensionsand to the needed width of the frame. The width of the frame has to besufficient to confer the suitable stiffness to the package, dependinginter alia on the total weight of the packaged products and on thepackage dimensions.

The multi-compartment package object of the presently disclosed subjectmatter may be particularly useful for the storage of products which arethin and flexible such as sliced food products or medical product likesurgery gloves, sterilized wipes, beauty wipes, patches, gauzes, stripsor soaked plasters or bands.

The package of the presently disclosed subject matter may be used tostore sliced food products such as cheese and processed meat. Otherpossible thin or sliced foods comprise fish and meat carpaccio, smokedfishes, piadina, crepes disks ready to be filled, sweet and salt doughready to be cut and/or cooked in the oven or fried or filled with astuffing and then cooked. It is also possible to insert different foodproducts in the same package in order to allow the consumer to have in asingle package a specific combination of food products.

For the purpose of the present description and of the claims whichfollow, except where otherwise indicated, all numbers expressingamounts, quantities, percentages, and so forth, are to be understood asbeing modified in all instances by the term “about”. Also, all rangesinclude any combination of the maximum and minimum points disclosed andinclude any intermediate ranges therein, which may or may not bespecifically enumerated herein.

EXAMPLES

A three-layer film having the composition reported in Table 1 and atotal thickness of 33 μm was coextruded through a 3-layer feedblock.

TABLE 1 Layer, thick- % ww ness Trade Name, Supplier, in the (μm)Chemical Nature layer Properties layer 1, EASTAR PETG 6763, 60% Density1.27 g/cm^(3;) 2.5 μm Eastman Chemical, Glass Transition 81° C.Polyethylene Melt Flow Rate (Cond. Terephthalate/Glycol 200° C./05.00 kg(G)) 2.8 g/10 min Viscosity Solution (Brook- field method) 0.75 mPa ·sec PRIMACOR 3440, 15% Comonomer content 9.7% DOW, Ethylene/AcrylicDensity 0.938 g/cm³ Acid Copolymer Melt Flow Rate (Cond. 190° C./02.16kg (G)) 10 g/10 min Vicat softening point 76° C. EASTAPAK 25% Density1.4 g/cm³ COPOLYESTER 9921, Melting Point (Tm) Eastman Chemical, 255° C.Polyethylene Terephthalate layer 2, EASTAPAK 60% Density 1.4 g/cm³ 24 μmCOPOLYESTER 9921, Melting Point (Tm) Eastman Chemical, 255° C.Polyethylene Terephthalate EASTAR PETG 6763, 40% Density 1.27 g/cm³Eastman Chemical, Glass Transition 81° C. Polyethylene Melt Flow Rate(Cond. Terephthalate/Glycol 200° C./05.00 kg (G)) 2.8 g/10 min ViscositySolution (Brook- field method) 0.75 mPa · sec layer 3, EASTAPAK 98%Density 1.4 g/cm³ 6.5 μm COPOLYESTER 9921, Melting Point (Tm) 255° C.Eastman Chemical, Polyethylene Terephthalate SUKANO G dc S503,  2% Vicatsoftening point Sukano AntiBlock and 82° C. Slip in PolyethyleneTerephthalate/Glycol

The three layers were then distributed through a flat die, having amulti-manifold system. The melt out of the die was quenched onto a chillrolls; electrostatic pinning was applied to increase the contact betweenmelt and chill roll kept at 19° C.

The so formed cast film was then biaxially oriented. The stretching wasdone simultaneously on a tenterframe, at ratios of 3.8:1 in both MD andTD directions, and at temperatures of 98° C. in the preheating zones and96° C. in the stretching zones. Before oven exit, the film was annealedat a temperature of 200° C.

The film properties are reported in Table 2 and 3, as well as thereference ASTM for the test method adopted for the measurements.

TABLE 2 Free Shrink ASTM D2732 temperature LD TD 120° C. 0 0 140° C. 2 0160° C. 5 2

TABLE 3 longitudinal transversal Mechanical Property direction directionat 23° C. (LD) (TD) ASTM elastic modulus (Kg/cm²) 36000 36000 D882tensile at break (Kg/cm²) 2250 2200 D882 elongation at break (%) 150 150D882

A machine Mondini Tray Lid E380 was used to manufacture 30 packagesaccording to the presently disclosed subject matter; Sealing conditionsapplied were: 190° C., 1 sec, 5 bar.

Each package (according to embodiment 1A) contained 4 compartments for atotal of 5 films; one slice of cooked ham was packaged in eachcompartment and each slice of cooked ham was about 1 mm thick. Fivefilms were superimposed in stack, alternating them with the products, toobtain four compartments.

The shape of the packages so obtained is shown in FIG. 1 and eachpackage was provided with a tab (4). The main dimensions of therectangular package were 160 mm (width)×205 mm (length), the sealingwidth was 5 mm and the distance between the two closest opposite sealswas 135 mm.

The packages were judged acceptable in terms of rigidity of the frame bythree panelists: in fact only a slight bending of the packages due tothe weight of the products was observed. In addition, the packages weremanually opened and the opening was really smooth due to the peelabilityof the films.

In conclusion, the multi-compartment flexible package of the presentlydisclosed subject matter does not require a supplemental tray. In factthe package is sufficiently rigid as such, thanks to the partialheat-induced crystallization of the crystallizable polymer incorrespondence of the sealing area. An embodiment of the present packagein use is not, or is only slightly, bent and remained substantially flatduring its handling. The absence of an additional tray allows asignificant reduction of plastic material as well as of manufacturingand disposal costs.

The partially crystallized area—which appears as a peripheralcircumferential continuous rigid frame—is obtainable during conventionalsealing of the package and advantageously does not require additionalsealing or forming operations or equipment.

Notwithstanding the much lower content of plastics, themulti-compartment package embodiments of the presently disclosed subjectmatter may provide for at least the same advantages of conventionalmulti-compartment packages, for instance:

-   preservation of single portions of different or same product(s),    allowing their individual use;-   improved conservation and durability of the packaged products,    including air sensitive foods such as sliced food products or    medical products, under modified atmosphere or vacuum;-   no contaminations (bacteria, odor, taste);-   prevention of sticking and breaking of sliced food, such as cheese    or processed meat, that occur when a high number of slices of these    products are stuffed in the same compartment of conventional    packages and are therefrom removed; and-   easy opening the compartment(s) which contains each single portion.

Embodiments of the present package may be considered as a “green”product that not only requires a significantly lower amount of plasticsbut can be easily recycled, when made of a single plastic material, orit may also be bio-degradable if composed of biodegradable polyesters,i.e. a multi-compartment package more eco-friend with respect toconventional multi-compartments packages currently on the market.

What is claimed is:
 1. A tray-less package comprising: i) two outermostfilms comprising crystallizable polymer; ii) at least two products; iii)at least one internal film comprising crystallizable polymer andinterposed between the at least two products and between the twooutermost films; and iv) a peripheral circumferential continuous rigidframe comprising a peripheral circumferential continuous seal whichseals the two outermost films and the at least one internal filmtogether in a sealing area and delimits at least two sealed compartmentseach enclosing at least a product of the at least two products, whereinthe crystallizable polymer is at least partially crystallized in thesealing area.
 2. The package according to claim 1 wherein only oneinternal film of the at least one internal film is interposed betweentwo adjacent products of the at least two products.
 3. The packageaccording to claim 1 wherein: the at least one internal film comprisesat least two internal films; and two internal films of the at least twointernal films are interposed between two adjacent products of the atleast two products.
 4. The package according to claim 1 wherein the atleast two sealed compartments comprise from 2 to 20 sealed compartments.5. The package according to claim 1 wherein the crystallizable polymeris selected from the group consisting of polypropylene homopolymers,polypropylene copolymers, high density polyethylenes, medium densitypolyethylenes, polyesters, polyamides, polystyrenes, and blends thereof.6. The package according to claim 1 wherein the two outermost films andthe at least one internal film each comprise at least 30% crystallizablepolymer by weight of the film.
 7. The package according to claim 1wherein the crystallizable polymer comprises one or more polyesters thatcrystallize under sealing temperatures from 140° C. to 220° C.
 8. Thepackage according to claim 1 wherein the crystallizable polymercomprises one or more polyesters having a melting point greater than220° C.
 9. The package according to claim 1 wherein the crystallizablepolymer in the sealing area has a percentage of crystallinity greaterthan 15%.
 10. The package according to claim 1 wherein the two outermostfilms and the at least one internal film each comprise a blendcomprising crystallizable polyester and at most 70% amorphous polyesterby weight of the blend, wherein the amorphous polyester has a glasstransition temperature lower than 115° C.
 11. The package according toclaim 1 wherein the two outermost films and the at least one internalfilm are sealable and peelable crystallizable plastic films.
 12. Thepackage according to claim 1 wherein the difference in the percentage ofcrystallinity of the crystallizable polymer within the sealing area withrespect to the crystallizable polymer outside of the sealing area of thepackage is at least 5%.
 13. The package according to claim 1 wherein thepercentage ratio between (i) the combined weight of the two outermostfilms and the at least one internal film with respect to (ii) the totalweight of the package is lower than 15%.
 14. A method of manufacturingthe tray-less package of claim 2 comprising the steps of: stacking insequence a first of the two outermost films, a first of the at least twoproducts, a first of the at least one internal film, a second of the atleast two products, and a second of the two outermost films;simultaneously sealing the two outermost films and the at least oneinternal film together in the sealing area (i) to at least partiallycrystallize the crystallizable polymer in the sealing area to form theperipheral circumferential continuous rigid frame and (ii) to delimit afirst sealed compartment and a second sealed compartment of the at leasttwo sealed compartments, wherein the first sealed compartment enclosesthe first product and the second sealed compartment encloses the secondproduct.
 15. The method of claim 14 wherein: the stacking step comprisesstacking a given number of additional internal films and the same givennumber of additional product in a film-product alternating arrangementbetween the second of the at least two products and the second of thetwo outermost films; and the simultaneous sealing step forms the samegiven number of additional sealed compartments.
 16. A method ofmanufacturing the tray-less package of claim 3 comprising the steps of:stacking in sequence a first of the two outermost films, a first of theat least two products, a first of the at least two internal films, asecond of the at least two internal films, a second of the at least twoproducts, and a second of the two outermost films; simultaneouslysealing the two outermost films and the at least two internal filmstogether in the sealing area (i) to at least partially crystallize thecrystallizable polymer in the sealing area to form the peripheralcircumferential continuous rigid frame and (ii) to delimit a firstsealed compartment and a second sealed compartment of the at least twosealed compartments, wherein the first sealed compartment encloses thefirst product and the second sealed compartment encloses the secondproduct.
 17. The method of claim 16 wherein: the stacking step comprisesstacking a given even number of additional internal films and half ofthe given even number of additional product in a film-film-productalternating arrangement between the second of the at least two productsand the second of the two outermost films; and the simultaneous sealingstep forms a number of additional sealed compartments that is equal tohalf of the given even number of additional internal films.
 18. A methodof manufacturing the tray-less package of claim 2 comprising the stepsof: stacking in sequence a first of the two outermost films, a first ofthe at least two products, and a first of the at least one internalfilm; sealing the first of the two outermost films and the first of theat least one internal film together in the sealing area to at leastpartially crystallize the crystallizable polymer in the sealing area anddelimit a first sealed compartment enclosing the first of the at leasttwo products; sealing the second of the outermost films to the firstsealed compartment (i) to at least partially crystallize thecrystallizable polymer in the sealing area of the outermost film, (ii)to delimit a second sealed compartment enclosing the second product ofthe at least two products, and (iii) to complete the peripheralcircumferential continuous rigid frame.
 19. The method of claim 18wherein: the at least two products comprises the first product, thesecond product, and one or more additional products; the at least oneinternal film comprises the first internal film and one or moreadditional internal films; and further comprising sequentially sealingeach of the one or more internal films to the first sealed compartmentto at least partially crystallize the crystallizable polymer in thesealing area of the one or more internal films and to delimit one ormore additional sealed compartments each enclosing one of the one ormore additional products.
 20. A method of manufacturing the tray-lesspackage of claim 3 comprising the steps of: sealing the first of the twooutermost films and the first of the at least two internal filmstogether in the sealing area to at least partially crystallize thecrystallizable polymer in the sealing area of the first films anddelimit a first sealed compartment enclosing the first of the at leasttwo products; sealing the second of the at least two internal films tothe second of the two outermost films (i) to at least partiallycrystallize the crystallizable polymer in the sealing area of the secondfilms, (ii) to delimit a second sealed compartment enclosing the secondof the at least two products, and (iii) simultaneously to attach thesecond sealed compartment to the first sealed compartment to completethe peripheral circumferential continuous rigid frame.
 21. The method ofclaim 20 wherein: the at least two products comprises the first product,the second product, and one or more additional products; the at leasttwo internal films comprises the first internal film, the secondinternal film, and two or more additional internal films; and furthercomprising sealing together each two of the two or more additionalinternal films (i) to at least partially crystallize the crystallizablepolymer in the sealing area of each of the two or more additionalinternal films, (ii) to delimit one or more additional sealedcompartments each enclosing one of the one or more additional products,and (iii) to attach each of the one or more sealed compartments to thefirst sealed compartment simultaneously with the sealing together ofeach two of the two or more additional internal films.
 22. A method ofmanufacturing the tray-less package of claim 2 wherein: the at least twoproducts comprises a first product, a second product, and a thirdproduct; the at least one internal film comprises a first internal filmand a second internal film; and comprising the steps of: sealing thefirst of the two outermost films and the first internal film together inthe sealing area to at least partially crystallize the crystallizablepolymer in the sealing area of the first films and delimit a firstsealed compartment enclosing the first product; sealing the secondinternal film and the second of the two outermost films to at leastpartially crystallize the crystallizable polymer in the sealing area ofthe second films and delimit a second sealed compartment enclosing thesecond product; interposing the third product between the first andsecond compartments; and attaching the second sealed compartment to thefirst sealed compartment to complete the peripheral circumferentialcontinuous rigid frame.
 23. The method of claim 22 wherein: the at leasttwo products further comprises one or more additional products; and theat least one internal film further comprises two or more additionalinternal films; further comprising sealing together each two of the twoor more additional internal films to at least partially crystallize thecrystallizable polymer in the sealing area of each of the two or moreadditional internal films and delimit one or more additional sealedcompartments each enclosing one of the one or more additional products;interposing one of the one of the one or more additional productsbetween each one of the one or more additional sealed compartments andthe adjacent sealed compartment; and sealing or gluing each of the oneor more additional sealed compartments to the first compartment or toanother of the one or more sealed compartments.
 24. A method ofmanufacturing the tray-less package of claim 3 comprising the steps of:sealing the first of the two outermost films and the first of the atleast two internal films together in the sealing area to at leastpartially crystallize the crystallizable polymer in the sealing area ofthe first films and delimit a first sealed compartment enclosing thefirst of the at least two products; sealing the second of the at leasttwo internal films and the second of the two outermost films to at leastpartially crystallize the crystallizable polymer in the sealing area ofthe second films and delimit a second sealed compartment enclosing thesecond of the at least two products; and sealing or gluing the firstsealed compartment and the second sealed compartment to complete theperipheral circumferential continuous rigid frame.
 25. The method ofclaim 24 wherein: the at least two products comprises the first product,the second product, and one or more additional products; the at leasttwo internal films comprises the first internal film, the secondinternal film, and two or more additional internal films; and furthercomprising sealing together each two of the two or more additionalinternal films to at least partially crystallize the crystallizablepolymer in the sealing area of each of the two or more additionalinternal films and delimit one or more additional sealed compartmentseach enclosing one of the one or more additional products; and sealingor gluing each of the one or more additional sealed compartments to thefirst compartment or to another of the one or more sealed compartments.